class WEBGL {

  static isWebGLAvailable() {

    try {

      const canvas = document.createElement('canvas');
      return !!(window.WebGLRenderingContext && (canvas.getContext('webgl') || canvas.getContext('experimental-webgl')));

    } catch (e) {

      return false;

    }

  }

  static isWebGL2Available() {

    try {

      const canvas = document.createElement('canvas');
      return !!(window.WebGL2RenderingContext && canvas.getContext('webgl2'));

    } catch (e) {

      return false;

    }

  }

  static getWebGLErrorMessage() {

    return this.getErrorMessage(1);

  }

  static getWebGL2ErrorMessage() {

    return this.getErrorMessage(2);

  }

  static getErrorMessage(version) {

    const names = {
      1: 'WebGL',
      2: 'WebGL 2'
    };

    const contexts = {
      1: window.WebGLRenderingContext,
      2: window.WebGL2RenderingContext
    };

    let message = 'Your $0 does not seem to support <a href="http://khronos.org/webgl/wiki/Getting_a_WebGL_Implementation" style="color:#000">$1</a>';

    const element = document.createElement('div');
    element.id = 'webglmessage';
    element.style.fontFamily = 'monospace';
    element.style.fontSize = '13px';
    element.style.fontWeight = 'normal';
    element.style.textAlign = 'center';
    element.style.background = '#fff';
    element.style.color = '#000';
    element.style.padding = '1.5em';
    element.style.width = '400px';
    element.style.margin = '5em auto 0';

    if (contexts[version]) {

      message = message.replace('$0', 'graphics card');

    } else {

      message = message.replace('$0', 'browser');

    }

    message = message.replace('$1', names[version]);

    element.innerHTML = message;

    return element;
  }
}

